Temperature T , in °C factor A factor B , in MPa 40 0.00001 0.357 40 0.00134 49.9 40 0.0015 53.5 40 0.002 57.9 40 0.0025 59.2 40 0.003 60.1 40 0.005 61.2 40 0.01 62.1 40 0.015 62.8 40 0.025 63.1 40 0.03 63.4 40 0.04 63.5 40 0.05 63.8 40 0.1 63.8